Space Eye: Hubble Problems Continue as Webb Telescope Advances | Space News

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NASA’s next big eye in the sky, the James Webb Space Telescope (JWST), with gold mirrors, underwent a key overhaul this week, bringing it closer to launch in November and observing new parts of the cosmos for Earth scientists .

This is good news for the U.S. space agency, which has spent the past few weeks trying to fix problems with its current window into the universe, the Hubble Space Telescope.

The famous telescope that has revolutionized our understanding of the cosmos for more than three decades is experiencing a technical error. According to NASA, the Hubble Space Telescope payload computer, which powers the spacecraft’s scientific instruments, suddenly crashed on June 13th.

During its more than 30 years in the sky, the Hubble Space Telescope has captured stunning images such as that of the Messier 106 galaxy. [File: STScI/AURA, R Gendler via AP]

As a result, on-board instruments intended for taking photographs and collecting data do not currently work. The best and brightest of the agency have been working diligently to recover the aging of the telescope online and have done a lot of testing, but it seems they still can’t figure out what went wrong.

“It’s just the difficulty of trying to fix something that revolves around 400 miles [653 million kilometres] on the head instead of in the lab, “Paul Hertz, director of astrophysics at NASA, told Al Jazeera.

“If this computer was in the lab, it would be very quick to diagnose it,” he explained. “All we can do is send a command, see what data comes out of the computer, and then send it and try to analyze it.”

The legacy of Hubble

When Hubble was launched on April 24, 1990, scientists were excited to observe the vast expanse of space with a new set of eyes, but they had no idea how much a telescope would change our understanding of the universe.

The telescope has looked into the farthest areas of space, spying as much as possible a distant galaxy never observed – one that formed just 400 million years after the big bang.

This image taken with the Hubble Space Telescope shows a hot galaxy appearing in stars that is farther away than any previously detected, from a time when the universe was only 400 million years old. [File: Space Telescope Science Institute via AP]

Hubble has also produced stunning galactic snapshots such as Hubble’s ultra-deep field.

Hundreds of thousands of ancient galaxies that formed long before Earth existed are captured in a single photograph: each galaxy was a vast and prosperous stellar center, where hundreds of billions of galaxies were born, lived and died ‘stars.

The light from these galaxies has taken billions of years to reach Hubble sensors, making it a time machine, taking us on a journey through time to see them as they were thousands of years ago. millions of years.

Hubble has also spied on our cosmic neighbors, discovering some of the moons around Pluto.

His observations showed us that almost all galaxies have a supermassive back hole in the center, and Hubble has also helped scientists create a vast three-dimensional map of an elusive, invisible form of matter that explains most of the matter. of the universe.

Called dark matter, the enigmatic substance is not seen. Scientists only know that it exists by measuring its effects on ordinary matter. Thanks to Hubble’s set of scientific instruments, scientists were able to create one 3D map of dark matter.

What went wrong

Scientists have been planning the inevitable demise of Hubble for quite some time. For the past 31 years, the telescope has seen much of its turmoil.

Shortly after its launch, NASA discovered that something was not quite right: Hubble’s main mirror was defective. The telescope is the only one in NASA history that was designed to be repaired by astronauts.

Astronauts Steven L Smith and John M Grunsfeld commissioned the Hubble Space Telescope during a December 1999 mission. [File: NASA/JSC via AP]

Throughout their lives (and during the agency’s shuttle program), groups of NASA astronauts have repaired and upgraded Hubble and its five different instruments.

When the space shuttle retired in 2011, it meant Hubble would be alone. If the telescope has problems, ground controllers should troubleshoot remotely.

So far, this has proven to be effective. That is, until June 13th.

Just after 16:00 EDT (20:00 GMT), a problem arose with the observatory’s payload computer putting the telescope and its scientific instruments into safe mode.

Hubble has two payloads on board: the main computer and a redundancy backup. These computers, called NASA-Spacecraft Computer-1 (or NSSC-1), were installed during one of the telescope’s service missions in 2009; however, they were built in the 1980s.

They are part of the command and data manipulation unit (SI C&DH) of the Scientific Instrument module to the Hubble Space Telescope that communicates with the telescope’s scientific instruments and formats the data for transmission to Earth. It also contains four memory modules (one main and three backups).

The current unit is a replacement that was installed by astronauts on the STS-125 launch mission in May 2009 after the original unit failed in 2008.

When the main computer crashed in June, NASA tried to activate its backup, but both computers experience the same error, suggesting that the real problem lies elsewhere in the telescope.

The team is currently studying the various components of the SI C&DH, including the power regulator and the data format unit. If one of these parts is the problem, engineers may need to perform a number of more complicated commands to switch to backing up these parts.

This image taken by NASA / ESA’s Hubble Space Telescope shows M66, the largest galaxy in Leo’s triplet. [File: NASA, ESA/Hubble Collaboration via AP]

NASA says it will take a while to fix the problem and move to backup systems if necessary. This is because activating these backups is a riskier maneuver than anything the computer has tried so far.

The operations team will need a few days to see how the backup equipment is working before it can resume normal operations. The backup has not been used since its installation in 2009, but according to NASA, “it was thoroughly tested before installation on the probe.”

Part of the problem with Hubble is that the observatory was designed to be attended to directly. Without a space shuttle, there is no way to do it.

“The biggest difference between the previous numbers and this one is that now there is no way to replace the pieces,” John Grunsfeld, a former NASA astronaut, told Al Jazeera.

But, he added, “the team working at Hubble are masters of engineering. I’m sure they will succeed. “

Looking to the future

The James Webb Space Telescope, launched in November, is expected to expand into Hubble’s legacy. The massive telescope, essentially a giant piece of space origami, will deploy its bright golden mirrors and look even further into the universe than Hubble could ever. Its infrared sensors will allow scientists to study stellar nurseries, the heart of galaxies and more.

Hubble has shown us that almost all galaxies have supermassive black holes at their centers, the brightest of which we call quasars. These incredibly bright objects can tell us a lot about the evolution of galaxies, as the rays and wind produced by a quasar help shape their host galaxy.

Previous observations have shown that there is a correlation between the masses of supermassive black holes and the masses of their galaxies, meaning that quasars could help regulate star formation in their host galaxy.

In August 2020, the Hubble Space Telescope captured this image of the planet Jupiter and one of its moons, Europe, on the left, when the planet was 653 million kilometers (406 million miles) from Earth. [File: NASA/ESA via AP]

“We see black holes at a time when the universe was only 800 million years old, almost as massive as the largest we see today, so they evolved very quickly,” said Chris Willott of the Canadian Space Agency and Al Jazeera.

“By studying their galaxies, we can see what the impact of these extreme black holes is on the early formation of stars in these galaxies.”

Through the eyes of Hubble, scientists cannot detect individual stars in galaxies with these ultra-bright quasars, but with Webb, scientists hope they can see not only individual stars, but also the gas from which they form. stars.

This means that the Webb telescope has the potential to truly revolutionize our understanding of the formation and evolution of galaxies, just as Hubble did for our knowledge of the universe over the past three decades.





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